1. Field of the Invention
The present invention relates to a chemical vapor deposition apparatus for uniformly and stably growing a deposition layer on a surface of a wafer by supplying reaction gas inwardly.
2. Description of the Related Art
In general, chemical vapor deposition (CVD) is used as an important method for growing various crystal layers on various substrates. CVD is advantageous in growing high-quality crystal layers as compared with a liquid deposition method; however, CVD is disadvantageous due to a relatively low crystal growing rate. To overcome this disadvantage, layers are simultaneously grown on a plurality of substrates during each cycle.
However, in the case where layers are simultaneously grown on a plurality of substrates, the substrates should be kept at the same temperature and exposed to the same flow of reaction gas so as to maintain the quality of layers grown on the substrates uniformly.
Examples of methods that can be used for the above-described purpose includes: a method of creating uniform gas flows along substrates using a plurality of injection tubes; a method of radially arranging a plurality of substrates around a rotation shaft and rotating the whole substrates on the same shaft (orbiting method); and a method of rotating a plurality of substrates individually (individual rotation method). Such methods of the related art may be used together or individually.